The $2.75 billion will come in the form of $1.9 billion in cash, a $125 million bond and about a 35% equity investment in Skype. The deal works out to slightly less than the $3.1 billion the Internet retailer paid for Skype in 2005.

“This is a great deal, unlocking both immediate and long-term value for eBay and tremendous potential for Skype,” said John Donahoe, eBay’s chief executive, in a statement.

EBay had hoped to use Skype to facilitate communication between auction buyers and sellers, but that never quite happened. The company announced its plans to part ways with Skype in April through an initial public offering, but the company said it also considered bids that offered “an attractive valuation.”

“When eBay acquired Skype, they had misconceptions about how this was going to fit into their business, and it didn’t work out the way they wanted it to,” said Vanessa Alvarez, Internet communications analyst with Frost Sullivan. “EBay never made the effort to integrate Skype; so with no long-term strategy, it was time to cut their losses.”

Donahoe said he is confident that Skype will prosper as a standalone company. He added that eBay wanted a deal in which it maintained a stake in the Internet phone business. “But it does not have synergies with our e-commerce and online payments business,” he said.

EBay will focus on its core brands, including Internet payment service PayPal and the Web site’s online auction house, according to Donahoe.

Despite eBay’s struggles to mesh the unit’s technology with its own, Skype has been a revenue driver and is growing. Skype had more than 480 million users by the end of the second quarter, and brought in $323 million so far this year. Last year, Skype revenues grew 44% from 2007, and EBay has estimated that the unit is on track to break $1 billion in revenue by 2011.

“We are extremely fortunate to have such a talented and seasoned group invest in our company,” said Skype Chief Executive Josh Silverman. “This is a group of investors and industry veterans that have a strong track record of taking the technology companies they own to the next level. With their know-how helping to guide our vision, Skype is poised to enter the next phase of its growth and development.”